1. Field of the Invention
The invention relates to a chassis for rail vehicles, particularly with inside-supported wheelsets, in which two wheelsets with a drive unit comprising a traction motor, transmission or coupling are mounted in a chassis frame, where at least parts of the drive unit are moveably elastically supported transversely to the travel direction via spring devices.
2. Description of the Related Art
In rail vehicles, a chassis executes lateral translational movements and rotary movements with respect to the vehicle. The dynamic reactions of the chassis as a result of a track fault become more severe with increasing speed as a result of the conical bearing surfaces of the wheels. This dynamic reaction, in the form of a rocking motion, is the reason for a critical speed, beyond which a vehicle can no longer be operated. A number of chassis parameters influence this critical speed, in addition to the conicity of the bearing surfaces of the wheels, rigidity of the wheelset mounting, wheel diameter, and, also the masses coupled to the wheelset. In this way, both the mass and also the rigidity and damping are important.
EP 0444016 B1 discloses a chassis in which the drive motor is rotatably mounted on the chassis frame at its end disposed in the travel direction, where at the opposite end the motor is connected to the chassis frame by way of leaf springs running in a perpendicular manner. The leaf springs are clamped with their ends between the motor and the chassis frame. As a result, the drive motor is suspended elastically and can oscillate elastically at right angles to the travel direction.
A chassis for electrical locomotives is likewise known from EP 0979190 B1, in which the drive motor can be moved in a translational manner at right angles to the travel direction of the vehicle, in order to play the role of an inertia damper. Here, the drive motor is suspended on the side of the axis with the aid of a suspension arm and on the side of the motor via two suspension arms on the chassis frame.
With these known chassis, the spring devices are always supported directly against the chassis frame. This is disadvantageous in that the spring travel is relatively large, it typically lies between the chassis frame and wheelset in the region of the drives at 25 to 50 mm vertical spring compression and at 15 to 35 mm spring expansion. In the transverse direction, an additional approximately +/−10 mm is also required for drive movements. This spring travel is not provided by the design of the drives but, instead, by the chassis construction, and can therefore also not be optimized to the drives so that on account of the relatively large oscillation amplitudes, the space available within the chassis frame is reduced for the drive unit, and drive motors with a higher performance are more difficult to accommodate.